1. Field of the Invention
The present invention relates to a means for a balancing the masses of a punching machine having a crank- or eccentric, respectively, shaft supporting via frictionless bearings the punch connecting rods which are pivotably connected to the ram of the punching machine, the mass balancing means having counterbalance weight means guided for vertical movement in the punching machine frame and operative for a counterbalancing of the oscillating forces, and having further counterbalance weight means operative for a counterbalancing of the rotating forces.
2. Description of the Prior Art
The oscillating counterbalancing weights of known punching machines are commonly driven by a rod. To this end one end of a respective rod is pivotably mounted to the oscillating counterbalance weight and oscillates in operation, whereagainst the opposite end of this rod is supported on a crankshaft and accordingly rotates in operation. This crankshaft drives also the punch connecting rod driving the ram of the punching machine.
In order to counterbalance the rotating forces relatively large masses are necessary and conclusively the rotating portion of the rod pivotably mounted to the counterbalancing weight of known punching machines is exceedingly heavy. This leads, however, to the fact that in case of lateral pivoting movements of this rod extremely large plus/minus moments are generated in the rod, which moments are transmitted via the respective guiding means of the moving parts of such punching machines onto the machine frame. This leads conclusively to problems regarding the supporting of the machine on its respective foundation. A design incorporating a short rod with the object to decrease the lateral swinging out movements of the rod is due to design reasons hardly possible because such rod interconnects moving structural members, which members need a space in order to carry out their movements and accordingly certain demands are made regarding the length of such rod.